Conventionally, Patent Document 1 listed below describes an example of this type of valve opening/closing timing control device.
In order to be able to swiftly start up an internal combustion engine and be able to start control for changing the relative rotation phase immediately after startup, this device includes a supply/discharge means for supplying and discharging working fluid to and from a phase changing mechanism and a supply/discharge means for supplying and discharging working fluid to and from a lock mechanism. It is described that this device has a configuration in which, particularly when performing startup when the relative rotation phase is at the lock phase, firstly working fluid is supplied to the phase changing mechanism that controls the relative rotation phase, and then after it has become possible to change the relative phase, working fluid is supplied to the lock mechanism to cancel the locked state.
With this configuration, it is possible to supply working fluid to a phase converting mechanism while maintaining the relative rotation phase at the lock phase, which is suited to startup of the internal combustion engine, and it is possible to increase the flow rate of the working fluid so as to complete the operation of filling the phase converting mechanism with working fluid in a short period of time. As a result, the lock mechanism release timing becomes earlier. Furthermore, as a result of releasing the lock mechanism earlier, advancing and retarding control can be performed immediately, and it is possible to obtain a valve opening/closing timing control device that is superior in terms of startup performance and response.